Summary (tl;dr)

The decommissioned U.S. Navy guided-missile frigate ex-USS Klakring was intentionally sunk in a joint U.S.-UK naval exercise, "Atlantic Thunder 2026," off the coast of Scotland to test advanced weapon systems and enhance military interoperability.

Essential Background

The USS Klakring, an Oliver Hazard Perry-class guided-missile frigate, was commissioned into the U.S. Navy in 1983 and decommissioned in 2013. For thirteen years following its decommissioning, the vessel was stored at the Philadelphia Naval Inactive Ship Maintenance Facility. In August 2026, the Klakring was towed from Philadelphia across the Atlantic to Scotland, where hazardous materials were removed in Campbeltown in preparation for its role as a target in a sinking exercise, ensuring compliance with environmental regulations.

The Full Story

From September 14 to 25, 2026, the ex-USS Klakring became the centerpiece of Exercise Atlantic Thunder 2026, a multi-domain live-fire sinking exercise (SINKEX) led by the U.S. 6th Fleet and involving U.S. and UK naval and air forces. During the exercise, the frigate was subjected to live-fire engagements from various platforms, including an SM-6 missile from the USS Paul Ignatius, Naval Strike Missiles (NSM) from the Royal Navy's HMS Portland, and Sea Venom missiles from an 815 Naval Air Squadron Wildcat helicopter. Guided bombs from U.S. Air Force F-15E Strike Eagles also struck the vessel. The final blow, which ultimately sank the ex-USS Klakring, came from a Mk 48 Advanced Capability torpedo fired by the newly commissioned Virginia-class attack submarine USS Massachusetts. This exercise was designed to validate surface weapon kill chains, build resilient kill webs, and demonstrate strategic messaging through kinetic action. It also marked the first operational firing of the Royal Navy's new NSM against a warship target and the first live firing of a Sea Venom missile from a Wildcat helicopter against a representative maritime target.

Why It Matters

This SINKEX highlights the robust lethality and interoperability between the United States and the United Kingdom, sending a clear message to potential adversaries about the combined strength of their naval forces. The exercise provided invaluable real-world data for evaluating weapon effectiveness against a genuine warship hull, rather than a purpose-built range target. Sensors installed on the ex-USS Klakring collected crucial data for post-exercise battle damage assessments and will inform future analysis of system failures and repair requirements. Furthermore, the successful operational deployment of the Royal Navy's new NSM and Sea Venom missiles represents a significant milestone, confirming their modern maritime strike capabilities for future surface warfare missions.

Geographic Location

• Atlantic Ocean, 150 nautical miles offshore of the MoD Hebrides range, northwest Scotland, United Kingdom (SINKEX during Exercise Atlantic Thunder 2026)
• Philadelphia Naval Inactive Ship Maintenance Facility, Philadelphia, Philadelphia County, Pennsylvania, United States (where ex-USS Klakring was stored after decommissioning)
• Campbeltown, Argyll and Bute, Scotland, United Kingdom (where hazardous materials were removed from the frigate)